GE 8502-BI-DP Motor Starter Contactor

Description

Product Model: GE 8502-BI-DP
Product Brand: GE (General Electric)
Product Series: GE 8500 Motor Control Series

Product Features:

• NEMA Size 1 magnetic contactor for motor control applications
• 3-pole design suitable for AC power circuits
• High mechanical endurance and electrical reliability
• Designed for demanding industrial environments and motor starting duty

Applications & Industry Context

Industrial motor control systems are the foundation of manufacturing, processing, and power distribution. Every conveyor, pump, and compressor depends on a reliable contactor to start and stop motors safely under load. The GE 8502-BI-DP plays a crucial role in these systems as a trusted magnetic contactor from General Electric’s time-proven 8500 Series.

Found in environments such as water treatment plants, steel mills, chemical refineries, and HVAC control panels, the GE 8502-BI-DP ensures smooth motor engagement with dependable mechanical performance. It’s designed for heavy-duty service, managing the electrical surge of motor starting currents while protecting downstream components.

For operators running 3-phase induction motors, having a contactor that can consistently handle repetitive switching cycles is vital. The GE 8502-BI-DP is known for precisely that—stability and endurance under continuous operation. In many facilities, you’ll find these contactors still running after decades of service, a testament to GE’s industrial design standards.

Its application range extends beyond traditional motor starting. Engineers often use the GE 8502-BI-DP in capacitor switching, resistive heating control, and even as part of complex control relay assemblies for automation panels. Whether in a manufacturing line or a utility substation, its NEMA-rated reliability keeps processes moving safely and efficiently.

Technical Features & Benefits

The GE 8502-BI-DP is a 3-pole NEMA Size 1 contactor designed for AC control circuits up to 600 volts. The model typically comes with a 120V AC coil, though other coil voltages can be configured depending on control requirements.

The contactor’s key advantage lies in its construction. Heavy-duty silver alloy contacts ensure long electrical life and minimize pitting or oxidation over time. The arc chutes are designed to quickly extinguish arcs upon contact separation, extending both electrical and mechanical longevity.

A few features that set the GE 8502-BI-DP apart include:

• Rugged NEMA Design: Built to meet or exceed NEMA standards for size, duty, and insulation, ensuring consistent performance in harsh conditions.
• Long Life Expectancy: Rated for tens of thousands of electrical operations under full load and hundreds of thousands mechanically.
• Compact Layout: Despite its durability, the module fits neatly within standard enclosures or control panels.
• Ease of Service: Field-replaceable contact kits and coils make maintenance straightforward and cost-effective.
• Compatibility: Works seamlessly with GE overload relays, auxiliary contact blocks, and control circuit accessories.

When compared to IEC-style contactors, the GE 8502-BI-DP offers more robust mechanical strength and is often preferred in North American industries where long-term reliability outweighs compact form factor.

For maintenance technicians, the GE 8502-BI-DP is easy to recognize—its frame and contact layout have remained consistent across generations. Spare parts are interchangeable across the 8500 Series, simplifying logistics for large facilities.

Product Role & System Fit

Within an electrical control system, the GE 8502-BI-DP functions as the primary contact interface between the control circuit and the power circuit. When the coil energizes, it magnetically pulls the movable contacts into the closed position, completing the circuit and powering the connected motor or load. When the control circuit de-energizes the coil, spring tension forces the contacts apart, safely interrupting current flow.

In a typical installation, the contactor works alongside:

• GE CR324 Overload Relays to provide motor overload protection
• Push-button stations for start/stop control
• Control transformers for proper coil voltage supply
• Circuit breakers or fuses for upstream fault protection

The GE 8502-BI-DP fits easily into new panels or as a replacement for legacy GE contactors without the need for rewiring or adapter plates. It’s a drop-in solution for engineers maintaining or upgrading older GE motor control centers (MCCs).

Additionally, the 8500 Series is known for its modular design. Accessories such as auxiliary contacts, mechanical interlocks, and surge suppressors can be added without major modification—allowing system designers to tailor the contactor’s function to specific operational requirements.

Technical Specifications

Installation & Maintenance Insights

Installing the GE 8502-BI-DP requires proper handling and alignment within the control panel or MCC section. Always ensure the coil voltage matches the control circuit supply before energizing. Misapplication of coil voltage is one of the most common causes of premature failure.

The contactor should be mounted vertically on a firm, vibration-free surface. When wiring, maintain the correct phase sequence and tighten terminal screws to the recommended torque. For three-phase motor circuits, load and line conductors should be sized appropriately based on the motor current rating.

During maintenance, visual inspection of contact faces and arc chutes is critical. Contacts showing heavy pitting or discoloration should be replaced using genuine GE contact kits. Coils can also be swapped in the field with minimal downtime.

One practical tip from experienced electricians: periodically check the mechanical operation by manually depressing the armature with power disconnected. The motion should be smooth and spring return should be firm—any binding indicates the need for cleaning or lubrication.

Related Models

• GE 8502-SA-DP – NEMA Size 0 contactor for small motor loads
• GE 8502-BA-DP – NEMA Size 1, similar function with alternate coil voltage
• GE 8502-CA-DP – NEMA Size 2 for medium-duty motors
• GE 8502-FA-DP – NEMA Size 3 contactor, 3-phase up to 50 HP
• GE 8502-NO-DP – NEMA Size 4 heavy-duty version
• GE 8536-SDG2 – Combination starter with overload relay
• GE CR306B0 – IEC-style contactor alternative for compact control panels